1. Field of the Invention
The present invention relates generally to electrical indicators, and in particular, to electrical indicators that provide a visual indication of operating load current.
2. Description of the Related Art
Electrical devices are used in many applications and can be either portable or permanently mounted. Each of these devices has a specific purpose and provides the user with differing means to identify proper operation. Some electrical devices produce audible noise which indicates that it is functioning and consuming electrical current from a given power source. These types of electrical devices include, but are not limited to, bells whistles, horns, sirens, and speakers. Other electrical devices provide visual feedback that indicates that electrical current from a given power source is being consumed. Some of these electrical devices can include, but are not limited to, fans, lights, material agitators, or driven mechanical systems such as belts and gears. There are also electrical devices that provide vibratory feedback when consuming electrical current from a power source. Examples of electrical devices that create vibrations can include, but are not limited to, motors, pumps, reciprocating machines, and sanders. Many of these electrical devices create all or some of these feedback modes. However, there are some electrical devices that do not create any of these feedback modes to the user. Likewise, an electrical device may be located in such a way that the user cannot sense the feedback of the device. Since no audible, visible, or vibratory feedback mode is generated, proper operation of the device will be difficult to identify.
A type of electrical device that generally does not create any audible, visible, or vibratory feedback to the user is electrical heating circuits. Electrical heating circuits consume electrical current when electricity flows through wires or elements that have a specific resistance to electrical current flow. This resistance generates heat within the wire which can be felt, but in some cases not directly seen or heard. Proper operation of this quiet, invisible, and non-moving electrical device is difficult to identify without touching. Touching such an electrical device can be dangerous owing to potential electrical shock or flesh burns from high temperatures. Some of these applications can include, but are not limited to, vehicle engine heaters, pipe and roof gutter heat tapes, and electrical heating pads for animals.
Occasionally, these heating circuits and other electrical devices are mounted in locations where it is difficult or impossible to obtain any type of proper operation feedback by the user. Examples of this situation could be, but are not limited to, devices that are installed a distance from the user or if the device is installed in confined and insulated space.
Therefore, in cases where heating circuits or electrical devices cannot be readily identified as operating properly, an electrical current flow indicator is needed.